If you have a network connection of a certain speed available on your phone, you expect receive data at roughly that speed, more or less. That’s how it works. Except that’s not how it’s been working for Netflix: the popular streaming video service was moving at a fraction of what users expected, on Verizon and AT&T networks. Consumers were all ready to line up and blame their mobile carriers, but the wireless companies weren’t the ones screwing around with anything, as it turns out. Netflix was.

The Wall Street Journal confirmed late last night that for the the last five years, Netflix has been capping their own mobile data streams at 600 Kbps on most wireless networks around the world.

The reasoning? If you hit your data cap and get socked with overage fees you won’t be watching any more Netflix this month — and you might cut back in future months, too. Therefore, in the interest of keeping customers watching and subscribing, they throttled the streams.

In terms of data usage, it’s easy to see why they chose that tactic. When we did the math on HD video a while back, Netflix was recommending a connection of 5MBps or faster in order to view HD video content… and their HD video streams used about 3 GB of bandwidth per hour. We calculated that viewing a lot of video (like, say, the entire 62-episode run of Breaking Bad) would put you so far over your average mobile data cap as to be completely ludicrous. In fact with those numbers, you’d go over a 3 GB data plan — Verizon’s “medium” — in a single episode.

Except millions of people with 3GB or 10GB data plans manage to watch Netflix for a few hours a month without going hundreds of dollars over their limits. So what gives?

Netflix gives.

Although your average modern mobile 4G LTE network can easily download data at speeds between 10 and 50 Mbps, the throttled Netflix streams are capped at less than 5 Mbps, allowing you to stroll, rather than sprint, towards your monthly data cap. You’ll still get there if you’re not using WiFi when you can, but it’ll take longer.

But wait: Netflix admitted to doing it for Verizon and AT&T customers, but not for T-Mobile or Sprint. Why not? Because “historically those two companies have had more consumer-friendly policies,” Netflix told the WSJ. Specifically, they mean the practice of throttling down data instead of charging overage fees. Watching too much Netflix in one week might mean you can’t for the next three weeks, but it won’t make you broke. And consumers are very sensitive to hits in the wallet region.

(T-Mobile customers, however, may still see reduced-quality Netflix streams thanks to the carrier’s BingeOn program.)

An AT&T representative told the WSJ, “We’re outraged to learn that Netflix is apparently throttling video for their AT&T customers without their knowledge or consent.” And while Netflix customers now have knowledge, there’s a decent case to be made that they didn’t exactly consent.

However, now that they’ve been called out on their behavior, Netflix says they’re working on ways to give consumers some say. They are “exploring new ways to give members more control in choosing video quality,” they told the WSJ, as well as soon launching a “mobile data saver” that will allow subscribers to tinker around with their mobile streaming settings.

Netflix Throttles Its Videos on AT&T, Verizon Networks [Wall Street Journal]

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